The teen has explained he had no choice but to snub Manchester United last summer.
“The complex, the fields, I just saw how professional it all was. I was really impressed at Chelsea.
“I want to develop into a big, strong striker who is also good at playing football. I want to be one of the best strikers in the world.
“If I'm working hard for that goal, there are many chances for me to play at a beautiful club at a high level in three years time. I hope that will be Chelsea's first team, of course.
“For me, Chelsea is the perfect match."